There has been an increased incidence of idiopathic pulmonary hemorrhage and hemosiderosis in infants in the Cleveland, Ohio area. A case- control investigation directed by the Centers for Disease Control and Prevention has found an association between the case infants and a toxigenic fungus, Stachybotrys atra, in their home environments. The spores of this fungus contain several classes of toxins including trichothecenes, potent protein synthesis inhibitors known to be neurotoxic. Several of the infants have had acute neurological involvement as part of their clinical picture, usually in the form of seizures and/or marked irritability. This has occurred under circumstances where there has not been sufficient hypoxia to explain sysmptoms. Most of the infants have appeared to recover without readily detected neurological deficits. However, exposure at an early age to the mycotoxins implicated in this disorder may pose additional risks of more subtle developmental difficulties. The objective of this study is to provide detailed longitudinal information regarding the physical, neurological, and cognitive development of infants affected with pulmonary hemorrhage/hemosiderosis. The hypothesis is that early exposure of infants to environmental mycotoxins sufficient to produce pulmonary bleeding will also lead to neurodevelopmental deficits detectable by standard psychometric testing.